Device for detecting and evaluating objects in the surroundings of a vehicle

ABSTRACT

An apparatus  1  for detecting and evaluating objects in the vicinity of a vehicle, having transmitting and receiving means for electromagnetic radiation in the Gigahertz range, includes at least one antenna protected by a radome  11   a   , 11   b . The radome  11   a   , 11   b  is designed as lens-shaped in such a way that beam focusing and/or beam pivoting of the broadcast electromagnetic radiation is made possible.

PRIOR ART

The invention relates to an apparatus for detecting and evaluatingobjects in the vicinity of a vehicle, as generically defined by thepreamble to claim 1.

An apparatus for detecting and evaluating objects in the vicinity of avehicle of this generic type is known from German Patent Disclosure DE199 63 005 A1 of the present applicant. It includes a pulse radar sensorwith transmitting and receiving means for transmitting and receivingelectromagnetic waves in the Gigahertz range. The electromagnetic wavesare broadcast and received by an antenna. Typically, to protect suchantennas against harmful environmental factors, a so-called radome isprovided. This coined term radome means a spherical protective dome. Inthe present application, the term radome is also used for protectivemeans that are not spherical.

ADVANTAGES OF THE INVENTION

The invention offers the advantages in particular that because of thedesign of the radome, beam shaping and in particular beam propagationand/or pivoting are made possible. Beam propagation in a horizontalplane serves to broaden the detection range to an extent that could notbe attained with a conventional radome. Beam pivoting makes easyadaptation to the body shape of the particular vehicle possible and thusoffers greater flexibility in installing the apparatus. Hence most ofthe components of the apparatus can be identical parts that can bemass-produced in large numbers. The adaptation to the radiationcharacteristic required for a particular vehicle type is then by meansof the radome designed according to the invention. The radomes can beconnected to the apparatus by means of a clip connection, makinginstallation especially easy.

Drawing

The apparatus of the invention will now be described in terms of theexemplary embodiments shown in the drawing. Shown are:

FIG. 1, the apparatus with its essential component groups in an explodedview;

FIG. 2, a cross section through the apparatus with a first exemplaryembodiment of a radome;

FIG. 3, a cross section through the apparatus with a second exemplaryembodiment of a radome;

FIG. 4, a cross section through the apparatus with a third exemplaryembodiment of a radome;

FIG. 5, a cross section through the apparatus with a fourth exemplaryembodiment of a radome; and

FIG. 6, a plan view on a striplike radome.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

FIG. 1 shows the apparatus 1 with its essential component groups in anexploded view. The apparatus 1 includes a tublike housing 10, 15, with ahousing tub 10 and a cap 15. The other component groups 11 a, 11 b and12 are mounted in the housing tub, which is closed with the cap 15 afterthese component groups have been installed. Reference numerals 10 a and10 b designate recesses in the bottom of the housing tub 10. Theserecesses are designed in slotlike form and extend parallel to oneanother in opposed regions of the bottom of the housing tub 10. Theelectromagnetic energy is broadcast through these slotlike recesses 10a, 10 b. Reference numerals 11 a, 11 b designate radomes. These radomesare designed essentially in striplike form and can be placed in thehousing tub 10 in such a way that they cover the slotlike recesses 10 a,lob in the bottom of the housing tub. Thus they close off the housing10, 15 from the outside in its bottom region and accordingly take overthe usual protective function of a radome, which shields off vulnerablehigh-frequency components from harmful environmental factors.

Especially advantageously, the radomes 11 a, 11 b can be connected tothe housing tub 10, or to the further component groups 12, by means of aclip connection. This makes installing the apparatus 1 substantiallysimpler and easier.

According to the invention, the radomes 11 a, 11 b are designed suchthat they not only perform the protective function known fromconventional radomes but also effect beam shaping and/or beamdeflection. This will be described below in terms of several exemplaryembodiments. FIGS. 2, 3, 4 and 5 each show a cross section through theapparatus 1 along a recess 10 a, 10 b in the bottom of the housing tub10. The exemplary embodiment shown in FIG. 2 illustrates in principlehow the radome 11 a, placed in the housing tub 10, covers the recess 10a in the bottom of the housing tub 10 and thus closes off the housing10, 15 from the environment. Especially advantageously, the radome 11 acan be clipped onto carriers 21 a, 21 b, 21 c, 21 d, which are connectedto the printed circuit board 12. In the process of installing the radome11 a, to assure a defined installed position, the essentially striplikeradome 11 a can expediently also be provided with spacers 20 a, 20 b,which preferably extend perpendicular to a main face of the radome 11 a.The radome 11 a preferably comprises a material that is highly permeableto high-frequency radiation in the Gigahertz range yet is weatherproof,since in everyday operation of a vehicle it is exposed to severeenvironmental conditions. A thermoplastic, in particular PBT(polybutylene terephthalate) has proved especially highly suitable. Tokeep the damping of the electromagnetic waves by the loss-impededmaterial of the radome 11 a, 11 b as slight as possible, the thickness Dof the radome 11 a, 11 b is reduced in the region of the recesses 10 a,10 b as far as the mechanical stability and technical productioncapabilities allow. In practice, a thickness D of the radome 11 a, 11 bof between 0.2 mm and 15 mm can be considered. An especially favorablecompromise in view of both a low damping value and still adequatemechanical stability is a thickness D of the radome 11 a, 11 b of 1.0mm. As FIG. 2 shows, for that purpose a recess is made in the outersurface of the radome 11 a, 11 b that reduces the thickness D of theradome in this region as desired. From a production standpoint, recessesthat are rotationally symmetrical are especially simple, in which casethe surface of the recess has the shape of a portion of a sphere or aspherical layer, for instance. However, arbitrary other structures ofthe recess can readily be attained from a production standpoint.Especially advantageously, the shaping of the recess serves the purposeof varying the beam, and in particular beam shaping and/or beamdeflection of the broadcast electromagnetic energy. In an especiallyadvantageous exemplary embodiment of the invention (FIG. 4), the recessis designed cylinder-symmetrically; that is, the outer surface of therecess is part of a cylindrical jacket face. As a result of such adesign, the radome 11 a, 11 b functions as a cylinder lens, whichenables beam propagation in a horizontal plane. As a result, anespecially favorable broadening of the detection range is made possible.

In a further exemplary embodiment (FIG. 5), the recess has the shape ofan asymmetrically embodied cylinder lens. As a result, beam deflectionor beam pivoting can be attained in a simple way. In turn as a result,the radiation characteristic of the apparatus can be adapted especiallysimply to different body shapes of vehicles. In this way, greatflexibility is obtained in terms of a favorable installation site forthe apparatus. It is understood to be within the scope of the presentinvention to provide still other lens shapes in conjunction with theradome 11 a, 11 b.

In an apparatus 1 that includes a plurality of antennas next to oneanother, a radome 11 a which, as shown in FIG. 6, has a plurality ofregions 60 that vary the electromagnetic radiation in the sense of beamfocusing and/or deflection proves to be expedient.

1. An apparatus for detecting and evaluating objects in the vicinity ofa vehicle, having transmitting and receiving means for generating,broadcasting and receiving electromagnetic radiation in the gigahertzrange, the transmitting and receiving means including at least oneradome-covered antenna, characterized in that at least a portion of theradome (11 a, 11 b) is embodied as lens-shaped in such a way thatfocusing and/or pivoting of the broadcast electromagnetic radiation ismade possible.
 2. The apparatus of claim 1, characterized in that atleast one recess is disposed in the outer surface of the radome (11 a,11 b).
 3. The apparatus of claim 1, characterized in that the recess isembodied rotationally symmetrically.
 4. The apparatus of claim 1,characterized in that the recess is embodied as a concave lens.
 5. Theapparatus of claim 1, characterized in that the recess is embodiedcylinder-symmetrically.
 6. The apparatus of claim 5, characterized inthat the recess is embodied as a cylinder lens which effects a beampropagation in a horizontal plane.
 7. The apparatus of claim 1,characterized in that the recess is embodied asymmetrically.
 8. Theapparatus of claim 7, characterized in that the recess is embodied as anasymmetrical cylinder lens.
 9. The apparatus of claim 1, characterizedin that the radome (11 a, 11 b) is embodied essentially in striplikeform.
 10. The apparatus of claim 1, characterized in that the thickness(D) of the radome (11 a, 11 b), at least in its region that is permeableto electromagnetic radiation, is between 0.2 mm and 15 mm, preferably1.0 mm.
 11. The apparatus of claim 1, characterized in that the radomes(11 a, 11 b) include spacers (20 a, 20 b), which extend perpendicular toa main face of the radome (11 a, lib).
 12. The apparatus of claim 1,characterized in that on the striplike radome (11 a, lib), a pluralityof regions (60) that vary the radiation in the sense of beam focusingand/or deflection are provided.
 13. The apparatus of claim 1,characterized in that the radome (11 a, 11 b) comprises a plasticmaterial.
 14. The apparatus of claim 13, characterized in that theradome comprises a thermoplastic, in particular PBT (polybutyleneterephthalate).